package com.r.pan.entity.dto;

import lombok.Getter;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

public class ImageCode {
    /**
     * 图片宽度
     */
    private int width = 160;

    /**
     * 图片高度
     */
    private int height = 40;

    /**
     * 验证码字符数
     */
    private int codeCount = 4;

    /**
     * 干扰线数量
     */
    private int lineCount = 20;

    /**
     * 验证码
     */
    private String code = null;

    /**
     * 验证码图片
     */
    @Getter
    private BufferedImage buffImg = null;

    Random random = new Random();

    public ImageCode() {
        createImage();
    }

    public ImageCode(int width, int height) {
        this.width = width;
        this.height = height;
        createImage();
    }

    public ImageCode(int width, int height, int codeCount) {
        this.width = width;
        this.height = height;
        this.codeCount = codeCount;
        createImage();
    }

    public ImageCode(int width, int height, int codeCount, int lineCount) {
        this.width = width;
        this.height = height;
        this.codeCount = codeCount;
        this.lineCount = lineCount;
        createImage();
    }

    public void createImage() {
        int fontWidth = width / codeCount;// 字体的宽度
        int fontHeight = height - 5;// 字体的高度
        int codeY = height - 8;

        // 图像buffer
        buffImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics g = buffImg.getGraphics();
        // Graphics2D g = buffImg.createGraphics();

        // 设置背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);

        // 设置字体
        Font font = new Font("Fixedsys", Font.BOLD, fontHeight);
        g.setFont(font);

        // 设置干扰线
        for (int i = 0; i < lineCount; i++) {
            int xs = random.nextInt(width);
            int ys = random.nextInt(height);
            int xe = xs + random.nextInt(width);
            int ye = ys + random.nextInt(height);
            g.setColor(getRandColor(1, 255));
            g.drawLine(xs, ys, xe, ye);
        }

        // 添加噪点
        float noiseRate = 0.01f; // 噪声率
        int area = (int) (noiseRate * width * height);
        for (int i = 0; i < area; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            buffImg.setRGB(x, y, random.nextInt(255));
        }
        String str1 = randomStr(codeCount); // 得到随机字符
        this.code = str1;
        for (int i = 0; i < codeCount; i++) {
            String strRand = str1.substring(i, i + 1);
            g.setColor(getRandColor(1, 255));
            // g.drawString(a,x,y);
            // a为要画出来的东西，x和y表示要画的东西最左侧字符的基线位于此图形上下文坐标系的(x，y)位置处
            g.drawString(strRand, i * fontWidth + 3, codeY);
        }
    }

    /**
     * 获取不含Oo0的字母数字随机字符串
     *
     * @param num 字符串长度
     * @return 随机字符串
     */
    private String randomStr(int num) {
        String str1 = "ABCDEFGHIJKLMNPQRSTUVWXYZabcdefghijklmnpqrstuvwxyz123456789"; // 没有Oo0
        StringBuilder str2 = new StringBuilder();
        int len = str1.length() - 1;
        double r;
        for (int i = 0; i < num; i++) {
            r = Math.random() * len;
            str2.append(str1.charAt((int) r));
        }
        return str2.toString();
    }

    /**
     * 获取随机颜色
     */
    private Color getRandColor(int fc, int bc) {
        if (fc > 255) fc = 255;
        if (fc < 0) fc = 0;
        if (bc > 255) bc = 255;
        if (bc < 0) bc = 0;
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

    public void write(OutputStream out) throws IOException {
        ImageIO.write(buffImg, "png", out);
        out.close();
    }

    public String getCode() {
        return code.toLowerCase();
    }
}
